title: A DNA microarray-based analysis of the host response to a nonviral gene carrier: a strategy for improving the immune response.
abstract: The purpose of this study was to investigate the host response to systemically administered lipid nanoparticles (NPs) encapsulating plasmid DNA (pDNA) in the spleen using a DNA microarray. As a model for NPs, we used a multifunctional envelope-type nano device (MEND). Microarray analysis revealed that 1,581 of the differentially expressed genes could be identified by polyethylene glycol (PEG)-unmodified NP using a threefold change relative to the control. As the result of PEGylation, the NP treatment resulted in the reduction in the expression of most of the genes. However, the expression of type I interferon (IFN) was specifically increased by PEGylation. Based on the microarray and a pathway analysis, we hypothesize that PEGylation inhibited the endosomal escape of NP, and extended the interaction of toll-like receptor-9 (TLR9) with CpG-DNA accompanied by the production of type I IFN. This hypothesis was tested by introducing a pH-sensitive fusogenic peptide, GALA, which enhances the endosomal escape of PEGylated NP. As expected, type I IFN was reduced and interleukin-6 (IL-6) remained at the baseline. These findings indicate that a carrier design based on microarray analysis and the manipulation of intracellular trafficking constitutes a rational strategy for reducing the host immune response to NPs.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Hatakeyama
authors.forename: Erika
authors.initials: E
authors.lastname: Ito
authors.forename: Momoko
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Akita
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kajimoto
authors.forename: Noritada
authors.initials: N
authors.lastname: Kaji
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Baba
authors.forename: Hideyoshi
authors.initials: H
authors.lastname: Harashima
mesh_terms: D000818:Animals; D018899:CpG Islands; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000276:immunology*; D007370:Interferon Type I / Q000096:biosynthesis / Q000235:genetics; D015850:Interleukin-6 / Q000096:biosynthesis; D008055:Lipids / Q000235:genetics* / Q000276:immunology*; D008297:Male; D051379:Mice; D053758:Nanoparticles / Q000008:administration & dosage* / Q000627:therapeutic use; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010455:Peptides; D010957:Plasmids / Q000235:genetics; D011092:Polyethylene Glycols / Q000378:metabolism; D021381:Protein Transport; D012333:RNA, Messenger / Q000096:biosynthesis / Q000097:blood; D013154:Spleen / Q000276:immunology; D051217:Toll-Like Receptor 9 / Q000235:genetics / Q000378:metabolism
chemical_list: D007370:Interferon Type I; D015850:Interleukin-6; D008055:Lipids; D010455:Peptides; D012333:RNA, Messenger; D051217:Toll-Like Receptor 9; C066951:GALA peptide; D011092:Polyethylene Glycols